Assembly for use as a clutch or a brake



ot.21,1958 T.LQFAWICK 2,857,031

ASSEMBLY FOR USE AS A -CLUTCH 0R A BRAKEv Y THOMAS LFAwlcK ATTORNEY Oct. 2l, 1958 T. l.. FAwlcK 2,857,031

' ASSEMBLY FOR USE As A CLUTCH 0R A BRAKE A Filed Feb. 17. 1954 s sheets-,sheet 2 ATTORNEY 7 United States VPatent C ASSEMBLY FOR USE AS A CLUTCH R A Thomas Fawick, Cleveland, Ohio, as'signor to Fawick Corporation, a corporation of Michigan Application Febmary 17, 1954, serial No. 410,804

' -1o Claims. l (Cl. 192-85) This invention relates to torque'sustaining clutches or brakes. i f

yItsc'hief objects are dependability, durability, compact.-

ness, ease of assembly and disassembly, especially for,

away, of parts of an assembly embodying lthe invention in its preferred form. v y

Fig. 2 is a section, on line 2-2 of Fig. 1, of the complete assembly.

Fig. 3 is a section on the indirect line 3-,3 of` Fig. l.,

Fig. 4 is a section on line 4-4 of Fig. l.

The particular embodiment here shown is a -clutch of the constrictng type. The drum, 10, Fig. 2, is splined upon a shaft 11, andA is formed with a frictional-engagement surface a which is gripped by a set of circumferentially spaced wear-shoes 19, 19. The mounting for the wear-shoes comprises a clutch element 13, which can be a -y-wheel, secured, as by bolts 14, 14, upon a shaft 1S, which can be a crank-shaft. Secured to the outer margin of the element 13, as by bolts 16, 16, is an over-hang clutch ring 17 of complex shape, this n'ng being formed at circumferentially spaced positions with openings extending radially through the ring.

As shown clearly in Fig. 1, each of these openings has a radially outer part providing a cylinder for a piston 18 and a radially inner part providing a guidew-ay 17b for a wear-shoe 19 and seats 17a, 17a for a pair of springsv 20, 20. vThe middle of each spring 20 bears against and constantly urges outwardly a projection 19a formed on the adjacent end of the base of the wear-shoe, Figs. 1 and 4. Each spring has an inwardly extending apertured end portion, Fig. 4, secured by a screw 21 to a face of the clutch ring for holding the spring in place when the Wear-shoe is moved, axially of the assembly, into or out of its guideway.

Cylinder-heads for all of the cylinders, at the outer ends, are provided by a cylindrical ring 22 that surrounds -the set of cylinders and is held upon the clutch-ring 17 -by means such as the screw 23, Figj3. Each cylinder is sealed to the ring 22, as its cylinder-head, by an O-ring.

24 set in an annular groove in the radially outer face of the clutch-ring 17, and each piston has for its packing an O-ring 25 set in an annular groove formed in the piston, and, if desired, a second such ring, 25a, likewise mounted. The invention of course does not exclude, however, the use of a standard metal piston ring instead of or in -addition to the O-ring.

For lightness each shoe Y19 is of webbed construction, as shown clearlyin Fig. 1 and vfor coactionwith the drum 10 is provided with an adhered friction facing 19h.

2,857,031 ICC., v Patented oei. 21, e

-For retaining each.wearshoe in its guideway while permitting it to moveradially of the `assembly for clutch engagement4 and disengagement, a retaining plate 26, Figs. 1 and 2, .hereoshown'` as being formed with an off-set, Fig. 2, is urged against a side face of the clutch-ring 17 by .a compression spring 27 interposed between the outer j face of the retaining plate and a nut 28 threaded upon aV screw stud 29 mounted in the ring 17 and extending through a hole in the yretaining plate. Each of the retaining plates is formed with a pair of pressed-out detents 30, 30 seating in respective recesses formed in the ring 17, under rthe force ofthe spring 27, to prevent undesired rotation of the retaining plate about the stud 29. Each retaining plate is formed also with a hole 31 for engagement ofthe plate by a suitable tool for pulling it suciently to overcome the` spring 27 and dislodge the detents 30 from their recesses so that the platecan be turned out of 4the wayof a wear-shoe being removed fromor moved into its guideway, axially of the assembly..

To'facilitate such manipulation of the wear-shoes each is formed, on its face adjacent the retaining plate, with a threaded hole 32 having in extension thereof a guide hole 33 lof smaller diameter, for engagement of the shoe by a tool 34, Fig. 2, having portions complemental to the.A

holes 32, 33. o

The clutch housing, 35, is formed with. an access opening provided with a removable closurecplate 36, Fig. 2,

at a position to which the wear-shoe assemblies can be`- brought in `succession for Yremoval orinsertion of wear shoes.

.For conducting actuatingiiuid to, and fromthe pistons i the clutch element 13 is formed with a radialpassage 37 and a passage 38 branching, therefrom. and leading into an Iannular groove 39 formed inthe face of the'member,` l 13 adjacent the clutch-ring 17. Those two members are sealed to each other on each side of the annular groove 39 by a radially inward O' ring 40 anda radially outward l 0ring 41 set in respective grooves in the clutch-ring 17.

At the position of each cylinder the annular `groove 39 is in communicationwiththe cylinder throughY one or more registered pairs of passages such as those shown ai 42, 43, Fig. 2, inthe members l17y and 2z, with an intervposed O-ring 44.r 'u Y l v 4 o The actuating fluid is supplied -to and vented fromthev passage 37 in the clutch element 13 through a rotary seal shown at the left of Fig. 2 and a second rotary seal shown at the right of Fig.2. v

The first mentioned `rotary seal comprises a non-ro tating ring 45 surrounding the `shaft 11 and. secured to the bearing housingof ythe shaft. kInea deep annular groove formed in the' axially inner face of therring 45 are slidably mounted a radially outer slip-seal ring 46 and,

spaced radially inward therefrom, a smaller-diameter slip-seal ring 47.

The outer slip-seal` ring 461s slidably sealed -to the i is heldY against a sholderfon' the shaftv 1,1,by a nuti53 and lock-washer 5'4."

The annular space between the slip-seal rings 46, 47 f is in communication, as `shown clearly vin Fig.,2, with alternatively usable inlet-outlet pipes 55, 56, for use f 3 alternatively of different clutch actuating uids, such as Qil or air.

The clutch-drum is splined upon the shaft 11 and retained thereon by a snap-ring 57 and` is held against the snap-ring by a spring 58 mounted between its hub and the nut 53.

Suitable passages as shown lead from the annular space between the slip-seal rings 46, 47 to an axial pas- Sage 59 in the Shaft 11- The passage 59 leads to. a recess of larger diameter formed in the `Iig'lltzljlttnfl @11d f2.1@ .of the shaft 11, in which recess is slidably sealed, by an O-ring 60, and backed by a spring 6 1, e tubular slip-seal member 62 having Slip-seal relation te a `fl.uidfeenductine disc or plug member 63 mounted in a complemented socket formed in the `clutch element 13 and havingcorn= munication with the passage 37 of the member 13. The plug member 63 is sealed to the wall of its socket, on each Side of the passage 37, by all Ofrtlg 64, 64 and iS retained in. its socket by a Snap-ring 65. A spacer ring 66 is mounted between-the SnepfriugGS andthe outer race of a pilot bearing 67 which journals the end of the shaft 1l in the clutch'element 13.

At a position within the circle of the adjacent O=ring 64 the shaft `1S is formed with a recess 68`in its end face and 'the plug member 63 is formed with a vent hole 69 leadingl from said recess, so that any leakage past the 0- ring can escape through the recess 68 passage 69 and the bearing 67. The building up of back pressure such as would prevent proper functioning of the self-energizing 0ring is thus prevented.

Provision for cooling the clutch (or brake) drum l0 comprises a cooling-liquid supply pipe 70 4from which liquid is discharged through a spout 71 into a chamber defined by an annular stamping 72 which surrounds the member 52 and is substantially sealed to it and to the member 45, to which it is secured, At its lowest part the stamping 72fis provided with an outlet spout 7-3 which terminates at a position to discharge cooling liquid onto a low part of the inner face ofthe rim of the clutch-drum 10. The radial web of the is formed with a set of cireumferentially spaced c )bliqueV holes 74, 74, Figs. 2 and 3, so that cooling duid will flow to the other side of the web. t

The bottom of the clutch housing 3S is provided with a drainage pipe 75, Fig. 3, lleading to the intake side of a pump, not Shown, for returning the, cooling uid to the. inlet pipe 70.

Preferably a suitable oil is-usedlas the cooling lfluid, so

that its circulation will provide lubrication the slipseal faces of the rotary seals andior the bearing 67. As it circulates independently of the actuating/'duid it can be chosen for suitable cooling well as lubricating characteristics.

The operation of the, assemblywill be manifest from the foregoing description. v

A11 important feature of the invention is that each piston 18 and its cylinder provide albralse-actuating or clutch-actuating motor individual to the associated Wearshoe 19. While in normal service each motor applies the same amount of braking pressure Atoits shoe as the other motors do to their respective shoes, all being connected to the same source lof' pressure iluid, yet each motor can be readily serviced or repaired as an individual motor, and the 'motors are `not all dependent upon continued functioning of avulnerable annular Ydiaphragm as in the case of some devices of the prior art.

l. An assembly comprising two-'relatively rotatable structures adapted for frictional, torque-sustaining engagement with each other, one off said structures having a frictional-engagement surfaceiand'zthe other` `of said structures comprising an actuating unit for: ffrctional engagement with said surface, said unit comprising a wearshoe structure, rigid means fixed in position in, relation to the axis and the orbit Of the. relative rotation of the said surface and integrally defining a pressure-fluid `cylinder chamber and, .inintegral .extension thereof, a guideway having torque-sustaining walls for guiding and wearshoe structure in its engaging and disengaging movements toward and from said frictional-engagement surface, a piston slidably mounted in said cylinder chamber for impelling said wear-shoe structure in its engaging movement, the said guideway-defining means integrally delining also a lateral passage for mounting and removal of the entire wear-shoe structure Wholly by movement thereof in a direction at right-angles to the direction of its engaging movement, said piston bearing against but being unattached to the said wear-shoe structure, the bearing surfaces of said piston and said wear-shoe structure being continuous and unbroken, the cylinder chamber and piston being individual to the single wear-shoe structure, and the entire Wear-shoe structure being insertable and removable through the said lateral passagewithout interference of any part of the means integrally dening the said cylinder chamber and the said guideway, with the piston remaining in the cylinder chamber.

2. An assembly as delined in claim l and including a removable. guideway wall for retaining the wear-shoe, `in its guideway and means pivotally mounting the removable guideway wall upon the means defining the guideway for turning said wall of the way of a wear-shoe being moved axially 0f the assembly into or out of its guideway.

3. An assembly as defined in claim 1 and including a removable guideway wall for retaining the wearfshoe in its guideway and in which the .removable guideway wall is pivotally mounted for turning it out of the way of a wear-shoe being moved axially of the assembly into or .out of its guideway, and including yielding means for urging said wall against the guideway-deiining means as a stop for ,positioning said wall and preventing its undesired rotation. i

4. An assembly as defined in `claim 1 .in which each wear-shoe is formed with means engageableby atool `for pulling the Wear-shoe, axially of the assembly, from the guideway, the said pulling means comprising the wall of a threaded hole in the wear-shoe and in Whiqhiihe weer, shoe is formed with a tool-guiding hole in yestension of but of smaller diameter than the recited threaded hole.

5. An assembly as dened in claim l `in whichthe re,- cited means defining the guideway is formed at each end of the wear-shoe space circumferentially 0f the assembly with an axially and circumferentially.extending springseat shoulder, each wearfsltoe is formed, at each of its ends with a spring-seat projection overlying and spaced from the said spring-seat shoulder, and the recited .yieldingl means comprises a spring interposed between'each spring-seat shoulder and the adjacent spring-seat proiection. l Y

6. assembly as dened in claim 5 in which each of the recited springs is of the leaf type and is secured at one of its ends to the guideway-dening means for ,retention of the spring in place when the wear-shoe is removed.

7. An assembly as dened in claim 1 and including a fluid-conducting shaft upon which the recited structure having the recited frictional-engagement surface is secured, a rotary seal surrounding the axis of said shaft for conducting actuating uid into said shaft, and a second rotary seal surrounding the axis of said shaft forv con. ducting actuating fluid through the other one of the re-V cited structures to the recited Cylinder chambers.

8. An assembly Comprising two relatively rotatable, fluid-conducting structures adapted for frictional', torque. sustaining engagement with each other and a .rotary seal for conducting actuating duid from one to the other of said structures, said rotary seal comprising alluid-.conducting slip-seal plug seated in a recess formed in and sur-A rounding the axis of one of said structures and in communication in a radial direction with aY huid-conductingv passage formed in that structure, and self-energizing sealsy y ing" means, at each side of the said passage, axially of the assembly, said sealing means surrounding the said plug and sealing it to the walls of the said recess, and the one of the said structures that is formed with the said recess being formed also with a vent passage extending from the oor of the said recess for venting to a region of lower pressure any fluid that may leak past the adjacent one of the said self-energizing sealing means.

9. An assembly comprising two relatively rotatable structures adapted for frictional, torque-sustaining engagement with each other, one of said structures having a frictional-engagement surface and the other of said structures comprising unitarily rigid means dening a rigidly connected set of circumferentially spaced, radially disposed cylinder chambers, pistons slidably mounted in the said chambers respectively, and a ring formed separately from the said means but constituting cylinder-head means common to said chambers, the said unitarily rigid means and the said ring-being formed with a single pair of mating cylindrical faces, and said ring providing closures for al1 of the said cylinder chambers and the said ring being `axially slidable from said unitarily rigid means.

10. An assembly as dened in claim 9 and including,

References Cited in the le of this patent UNITED STATES PATENTS 881,510 Warren et al. Mar. l0, 1908 899,953 Chadwick Sept. 29, 1908 1,047,713 Smith Dec. 17, 1912 2,028,152 Gray Ian. 21, 1936 2,060,826 Roberts Nov. 17, 1936 2,229,922 Heinze Ian. 28, 1941 2,304,030 Schmitter Dec. 1, 1942 2,324,979 Hatch July 20, 1943 2,498,123 Hobbs Feb. 21, 1950 2,588,985 Kutz Mar. 11, 1952 2,710,087 Picard June 7, 1955 2,720,866 Maki Oct. 18, 1955 2,823,777 Banker Feb. 18, 1958 FOREIGN PATENTS 636,240 France Jan. 7,r 1928 831,344 Germany Feb. 11, 1952 892,261 Germany Oct. 5, 1953 

